XO power management

Richard A. Smith richard at laptop.org
Thu Mar 24 09:15:08 EDT 2011

On 03/24/2011 08:55 AM, Ismael Schinca wrote:
> Thanks, for starters this is really useful, because it's not at all
> similar to what I've been observed. The computer powers off with battery
> levels between 10-15% and the led starts blinking around 5-10%. I'm
> using several batteries on the same XO 1.0 computer. Granted, the
> batteries are not fresh ones, but that's exactly what I am trying to
> figure out. How the battery behaviour changes when battery capacity
> starts to decrease over time.
> Any additional information will be most welcome.

What you are observing is exactly what will happen as the battery 
reduces capacity.  We don't have a calibration procedure so the SOC 
assumes 3100mAh.  The SOC is a mAh/1% counter.  After so many mAh it 
subtracts 1%.  The critical level is a voltage reading.  Its not coupled 
to the SOC.  So with a battery that has less capacity you will reach the 
critical level sooner.

Whats the serial number of your battery?  You may also want to run a 
olpc-pwr-log run with that battery so you can determine what the actual 
capacity of the battery is.

Richard A. Smith  <richard at laptop.org>
One Laptop per Child

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